The father of David Hicks, one of two Australians being held at Guantanamo Bay, trundled to Canberra's Capitol Hill last May from his home in Adelaide in a vain attempt to get some answers about his son. He appeared a lost and lonely figure. With his short stature and heavily etched face, Terry Hicks seemed rather bewildered traipsing through Parliament House - startled by the glare of TV cameras and reporters, and confronted with the reality that no Government politician was prepared to see him.

One press gallery observer recalled how during question time that day, when a Greens MP drew the attention of the Prime Minister to Terry Hicks's presence in the public gallery, the man half rose in his seat, unsure of whether he should be standing while John Howard was talking about him.

It was a melancholy image of a father who'd been wrenched out of his modest but comfortable life into an unfamiliar world as he struggled to help his son, who has been a prisoner of the Americans for more than two years without charge.

But the Terry Hicks of today, who has just finished making, with producer and director Curtis Levy, the documentary The President Versus David Hicks, is an altered, more self-assured man.

The film will premiere on Thursday on SBS, the first instalment in a new weekly slot of local documentaries called Storyline Australia. In making the film, Terry Hicks and Levy set out to challenge the image of David Hicks created by the Australian and US governments. Was Hicks really a traitor and a terrorist? And how was it that he came to be fighting with the Taliban in Afghanistan in 2002 when he was picked up by the Northern Alliance and delivered to the Americans?

What emerges from the film is a revealing insight, through extracts from the letters and poetry David Hicks wrote on his travels through Kosovo, Pakistan and Afghanistan, into the indoctrination of the 26-year-old into Islamic fundamentalism.

The film shows how David Hicks went from being a bit of a lost soul, a stockman and rodeo rider whose first job abroad was training horses in Japan, to someone who could be so moved by television footage of Muslims being killed in Kosovo that he joined the Kosovo Liberation Army. And to someone who could then pen a letter from Pakistan, where he went to study Islam, telling his family that it was God's will that he "go directly to the front", and that, should he meet his fate, the highest position in heaven was "to go fighting in the way of God against the forces of Satan".

As the progression of David Hicks's faith unfolds through the film, his father makes his own parallel journey. We see a man who had never travelled outside Australia before - whose world was turned upside down the day he came home from the football to receive a knock on his door from two ASIO officers informing him of his son's capture - subsequently resolve to go to Pakistan and Afghanistan to find out for himself what happened to his son.

Terry Hicks's travels take him to a bombed-out al-Qaeda camp where his son supposedly trained, and sees him come face to face with the Northern Alliance member who captured his son. And he emerges with an even stronger faith in his son's integrity.

Terry Hicks told The Guide he believed finding Islam "did [David] the world of good. I don't care what anybody says, he was a lot better in himself." He also believes his son was "just caught in the wrong place at the wrong time", and was trying to get out of Afghanistan when he was captured. For his part, Levy also is convinced Hicks was no terrorist but, rather, a foot soldier for Islam - "an adventurer who developed a very fervent belief in Islam and [who] felt that he was helping oppressed Muslims".

Both Terry Hicks and Levy concede the film leaves many questions unanswered. They will remain so until David Hicks is able to speak for himself. But what Levy hopes is the documentary will "help people to understand the personal journey that David's taken".

Levy adds: "It's up to people to react in any way they want to in terms of how they feel at the end of the film, but I would hope that they would see that a huge injustice has been done to David, no matter what he may have done."